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Publication numberUS20040015935 A1
Publication typeApplication
Application numberUS 09/818,097
Publication dateJan 22, 2004
Filing dateMar 26, 2001
Priority dateMar 26, 2001
Also published asEP1402358A2, US7020874, WO2002077804A2, WO2002077804A3
Publication number09818097, 818097, US 2004/0015935 A1, US 2004/015935 A1, US 20040015935 A1, US 20040015935A1, US 2004015935 A1, US 2004015935A1, US-A1-20040015935, US-A1-2004015935, US2004/0015935A1, US2004/015935A1, US20040015935 A1, US20040015935A1, US2004015935 A1, US2004015935A1
InventorsStepan Sokolov, David Wallman
Original AssigneeSun Microsystems, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Techniques for loading class files into virtual machines
US 20040015935 A1
Abstract
Improved techniques for loading class files into virtual computing machines are disclosed. These techniques provide a mechanism that will generally improve the efficiency of virtual machines by selectively loading information into a virtual machine. As will be appreciated, this allows a better use of the resources of the virtual machine. This is especially effective in virtual machines that operate with limited memory resources (e.g., embedded systems). In one embodiment, class files suitable for loading into a virtual machine are initially loaded into a memory portion (e.g., heap memory). Then, information that is needed to be loaded into the virtual machine is selected. Finally, only the selected information is loaded into the virtual machine.
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Claims(21)
What is claimed is:
1. A method of loading a class file into a virtual machine, said class file being associated with a class, and said virtual machine operating in an object-oriented computing system, said method comprising:
loading said class file into a memory portion of the computing system;
selecting information from said class file to be loaded into said virtual machine; and
loading said selected information from said memory portion into said virtual machine and not loading information not selected from the class file into the virtual machine.
2. A method as recited in claim 1, wherein the method further comprises:
encountering a request to a said class associated with a class file.
3. A method as recited in claim 1, wherein said selecting of information operates to select information from said class file that is likely to be used by the virtual machine.
4. A method as recited in claim 1, wherein said selecting of information operates to select information from said class file that is needed to be used by the virtual machine.
5. A method as recited in claim 1, wherein said selecting of information operates to select information that includes information associated with at least one method of said class.
6. A method as recited in claim 1, wherein said loading of only said selected information operates to create an internal representation of the class file in the virtual machine.
7. A method as recited in claim 6, wherein said internal representation of said class file includes a method reference portion.
8. A method as recited in claim 7, wherein said method reference portion includes a method name field, a method signature field, and a method code field.
9. A method as recited in claim 1, wherein said loading of only said selected information operates to populate said method name field, method signature field, and method code field with appropriate information or references to appropriate information.
10. A method as recited in claim 1, wherein said memory is a heap memory of said computing system.
11. A method as recited in claim 1, wherein the method further comprises:
determining whether an internal representation of the class file exists in the virtual machine; and
creating an internal representation of the class file in the virtual machine when said determining determines that an internal representation of the class file does not exist in the virtual machine.
12. A method as recited in claim 1, wherein the method further comprises:
determining whether said class file exists in said memory portion; and
loading said class file in said memory portion when said determining determines that said class file does not exist in said memory portion.
13. A method as recited in claim 1, wherein the method further comprises:
removing said class file from said memory portion.
14. A method as recited in claim 13, wherein said removing is performed on a Least Recently Used basis.
15. A method of loading a class file into a virtual machine, said class file being associated with a class, and said virtual machine operating in a computing system, said method comprising:
encountering a request to use at least one method of a class associated with a class file;
determining whether said class file exists in a dedicated heap memory portion;
loading said class file in said dedicated heap memory portion when said determining determines that said class file does not exist in said dedicated heap memory portion;
selecting information associated with said at least one method of said class;
determining whether an internal representation of the class file exists in said virtual machine;
creating an internal representation of the class file in the virtual machine when said determining determines that an internal representation of the class file does not exist in said virtual machine; and
loading into the virtual machine said selected information associated with said at least one method of said class and not loading into said virtual machine information that was not selected.
16. A method as recited in claim 15, wherein the method further comprises:
removing said class file from said dedicated heap memory portion on a Least Recently Used basis.
17. A method as recited in claim 15, wherein said selected information includes a method name field, a method signature field, and a method code field with appropriate information or references to appropriate information.
18. A method as recited in claim 15, wherein said internal representation includes a reference cell associated with said at least one method.
19. A computer readable media, including computer program code for loading a class file into a virtual machine, said class file being associated with a class, and said virtual machine operating in an object-oriented computing system, said computer program code comprising:
computer program code for loading said class file into a memory portion of the computing system;
computer program code for selecting information from said class file to be loaded into said virtual machine; and
computer program code for loading said selected information from said memory portion into said virtual machine and not loading information not selected from the class file into the virtual machine.
20. A computer readable media as recited in claim 19, wherein said computer program code for selecting of information operates to select information from said class file that is likely to be used by the virtual machine.
21. A computer readable media as recited in claim 19, wherein said computer program code for selecting of information operates to select information from said class file that is needed to be used by the virtual machine.
Description
    CROSS-REFERENCE TO RELATED APPLICATIONS
  • [0001]
    This application is related to U.S. patent application No. ______ (Att.Dkt.No. SUN1P809/P5500), entitled “IMPROVED FRAMEWORKS FOR INVOKING METHODS IN VIRTUAL MACHINES,” which is hereby incorporated herein by reference.
  • [0002]
    This application is related to U.S. patent application No. ______ (Att.Dkt.No. SUN1P810/P5510), entitled “IMPROVED METHODS AND APPARATUS FOR NUMERIC CONSTANT VALUE INLINING IN VIRTUAL MACHINES,” which is hereby incorporated herein by reference.
  • [0003]
    This application is related to U.S. patent application No. ______ (Att.Dkt.No. SUN1P814/P5417), entitled “IMPROVED FRAMEWORKS FOR LOADING AND EXECUTION OF OBJECT-BASED PROGRAMS,” which is hereby incorporated herein by reference.
  • BACKGROUND OF THE INVENTION
  • [0004]
    1. The Field of the Invention
  • [0005]
    The present invention relates generally to object oriented programming environments. More specifically, the invention relates to improved frameworks for loading class files into virtual computing machines.
  • [0006]
    2. The Relevant Art
  • [0007]
    Recently, the Java™ programming environment has become quite popular. The Java™ programming language is an object-based, high level programming language that is designed to be portable enough to be executed on a wide range of computers ranging from small devices (e.g., pagers, cell phones and smart cards) up to supercomputers. Computer programs written in the Java programming language (and other languages) may be compiled into Java virtual machine instructions (typically referred to as Java bytecodes) that are suitable for execution by a Java virtual machine implementation.
  • [0008]
    The Java virtual machine is commonly implemented in software by means of an interpreter for the Java virtual machine instruction set, but in general may be software, hardware, or both. A particular Java virtual machine implementation and corresponding support libraries together constitute a Java™ runtime environment.
  • [0009]
    Computer programs in the Java programming language are arranged in one or more classes or interfaces (referred to herein jointly as classes or class files). Such programs are generally platform independent (i.e., hardware and operating system). As such, these computer programs may be executed unmodified on any computer that is able to run an implementation of the Java™ runtime environment. A class written in the Java programming language is compiled to a particular binary format called the “class file format” that includes Java virtual machine instructions for the methods of a single class. In addition to the Java virtual machine instructions for the methods of a class, the class file format includes a significant amount of ancillary information that is associated with the class. The class file format (as well as the general operation of the Java virtual machine) is described in some detail in The Java Virtual Machine Specification by Tim Lindholm and Frank Yellin (ISBN 0-201-31006-6), which is incorporated herein by reference.
  • [0010]
    Generally, when a class file is loaded into the virtual machine, the virtual machine essentially makes a copy of the class file for its internal use. The virtual machine's internal copy is sometimes referred to as an “internal class representation.” In conventional virtual machines, the internal class representation is typically almost an exact copy of the class file. This is true regardless of whether the loaded information is likely to be used or is not used. For example, an exact copy of common Java classes (e.g., class PrintWriter), are loaded into the virtual machine. These classes typically have a large size. Thus, a common class, for example, class PrintWriter, may take up as much as 40 KiloBytes (40 K) of memory. However, typically, 90% of the class is not used during the execution of a computer program. This, of course, results in a grossly inefficient use of memory resources. In some circumstances, particularly in embedded systems which have limited memory resources, this inefficient use of memory resources is a significant disadvantage.
  • [0011]
    To further elaborate, FIG. 1 depicts a representation of a class file 100 inside a virtual machine. The class file 100 includes Methods A-Z portions that correspond to methods associated with a class. In addition, the class data 102 represents class data for the class. As will be appreciated by those skilled in the art, during typical execution of a program, only a small number of methods may be needed, for example, only Methods A and B may be needed. Nevertheless, all the methods associated with a class file are conventionally loaded. Similarly, only a data portion 104 may have been needed, but conventionally, all of the class data 102 is loaded. Thus, conventional techniques result in grossly inefficient use of memory resources which is a significant disadvantage, especially when memory resources are limited.
  • [0012]
    In view of the foregoing, improved techniques for loading class files into virtual computing machines are needed.
  • SUMMARY OF THE INVENTION
  • [0013]
    To achieve the foregoing and other objects of the invention, improved techniques for loading class files into virtual computing machines are disclosed. One aspect of the present invention seeks to provide a mechanism that will generally improve the efficiency of virtual machines by selectively loading information into a virtual machine. In other words, unlike conventional techniques where the entire class file is substantially loaded into the virtual machine, the inventive techniques can operate to load only a portion of the class file. As will be appreciated, this allows a better use of the resources of the virtual machine. The inventive mechanisms are especially effective in virtual machines that operate with limited memory resources (e.g., embedded systems). In one embodiment, class files suitable for loading into a virtual machine are initially loaded into a memory portion (e.g., heap memory). Then, information that is needed to be loaded into the virtual machine is selected. Finally, only the selected information is loaded into the virtual machine.
  • [0014]
    The invention can be implemented in numerous ways, including as a method, an apparatus, a computer readable medium, and a database system. Several embodiments of the invention are discussed below.
  • [0015]
    As a method for loading a class file into a virtual machine, one embodiment of the invention includes the acts of: loading the class file into a memory portion of the computing system; selecting information from the class file to be loaded into the virtual machine; and loading the selected information from the memory portion into the virtual machine and not loading information not selected from the class file into the virtual machine.
  • [0016]
    As another method for loading a class file into a virtual machine, another embodiment of the invention include the act of: encountering a request to use at least one method of a class associated with a class file; determining whether the class file exists in a dedicated heap memory portion; loading the class file in the dedicated heap memory portion when the determining determines that the class file does not exist in the dedicated heap memory portion; selecting information associated with the at least one method of the class; determining whether an internal representation of the class file exists in the virtual machine; creating an internal representation of the class file in the virtual machine when the determining determines that an internal representation of the class file does not exist in the virtual machine; and loading into the virtual machine the selected information associated with the at least one method of the class and not loading into the virtual machine information that was not selected.
  • [0017]
    As a computer readable media, including computer program code for loading a class file into a virtual machine, one embodiment of the invention includes: computer program code for loading the class file into a memory portion of the computing system; computer program code for selecting information from the class file to be loaded into the virtual machine; and computer program code for loading the selected information from the memory portion into the virtual machine and not loading information not selected from the class file into the virtual machine.
  • [0018]
    These and other aspects and advantages of the present invention will become more apparent when the detailed description below is read in conjunction with the accompanying drawings.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0019]
    The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
  • [0020]
    [0020]FIG. 1 depicts a representation of a class file inside a virtual machine;
  • [0021]
    [0021]FIG. 2 illustrates an object-oriented programming environment in accordance with one embodiment of the invention;
  • [0022]
    [0022]FIG. 3 is a block diagram of the internal class representation in accordance with one embodiment of the invention;
  • [0023]
    [0023]FIG. 4 is a diagrammatic representation of a reference cell in accordance with one embodiment of the present invention; and
  • [0024]
    [0024]FIG. 5 illustrates an exemplary loading method for loading a class file in accordance with one embodiment of the invention.
  • DETAILED DESCRIPTION OF THE INVENTION
  • [0025]
    As described in the background section, the Java programming environment has enjoyed widespread success. Therefore, there are continuing efforts to extend the breadth of Java compatible devices and to improve the performance of such devices. One of the most significant factors influencing the performance of Java based programs on a particular platform is the performance of the underlying virtual machine. Accordingly, there have been extensive efforts by a number of entities to provide improved performance to Java compliant virtual machines. In order to be Java compliant, a virtual machine must be capable of working with Java classes which have a defined class file format. Although it is important that any Java virtual machine be capable of handling Java classes, the Java virtual machine specification does not dictate how such classes are represented internally within a particular Java virtual machine implementation.
  • [0026]
    The present invention pertains to improved frameworks for loading class files into virtual computing machines. One aspect of the present invention seeks to provide a mechanism that will generally improve the efficiency of virtual machines by selectively loading information into a virtual machine. In other words, unlike conventional techniques where the entire class file is substantially loaded into the virtual machine, the inventive techniques can operate to load only a portion of the class file. As will be appreciated, this allows for a better use of the resources. The inventive mechanisms are especially effective in virtual machines that operate with limited memory resources (e.g., embedded systems). In one embodiment, class files suitable for loading into a virtual machine are initially loaded into a memory portion (e.g., heap memory). Then, information that is needed to be loaded from the class file into the virtual machine is selected. Finally, only the selected information from the class file is loaded into the virtual machine.
  • [0027]
    Embodiments of the invention are discussed below with reference to FIGS. 2-4. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments.
  • [0028]
    [0028]FIG. 2 is a representation of an object-oriented computing environment 200 in accordance with one embodiment of the invention. The object-oriented computing environment 200 includes a class file 202, a raw-class heap portion 204, and an internal class representation 206 of the class file 202. The internal class representation 206 illustrates the information that is loaded in a virtual machine operating in the object-oriented computing environment 200.
  • [0029]
    As shown in FIG. 2, the class file 202 can include associated Methods M1-Mn, as well as a data portion D. The class file 202 can be resident, for example, on a computer readable medium (e.g., compact disk, floppy disk, etc.) Furthermore, as will be appreciated, the class file 202 may be located anywhere in a distributed computing environment. Accordingly, in a distributed computing environment, the class file 202 may be transferred over a computer network from a remote location and can then be loaded into the virtual machine.
  • [0030]
    The raw-class heap portion 204 represents a portion of the memory of the object oriented computing environment 200 that is used to initially load the class file 202. This memory can be, for example, a memory portion of the object-oriented computing environment 200 that is dedicated to loading class files (i.e., dedicated memory). In contrast, the internal class representation 206 illustrates the information that is actually loaded inside the virtual machine. In this example, only the Methods Mi and Mj of the Methods M1-Mn have been loaded into the virtual machine. Similarly, only a portion Di of the class data D is loaded into the virtual machine. Furthermore, as will be appreciated by those skilled in the art, maintenance can be performed on raw-class heap portion 204. For example, class files can be removed from the raw-class heap portion 204 on a Least Recently Used (LRU) basis.
  • [0031]
    [0031]FIG. 3 is a block diagram of the internal class representation 206 in accordance with one embodiment of the invention. The internal class representation 206 can be, for example, implemented as a data structure embodied in a computer readable medium that is suitable for use by a virtual machine. As shown in FIG. 3, the internal class representation 206 includes a method information portion 210. The method information portion 210 can be arranged to contain or reference information relating to one or more methods. These methods can be, for example, Java implemented methods. Furthermore, as will be appreciated, the method information portion 210 can be implemented in various ways, for example, as a table similar to a table of method information implemented in a standard Java class file.
  • [0032]
    In addition to the method information portion 210, the internal class representation 200 includes a method reference portion 220 associated with the methods contained within the internal class representation 206. The method reference portion 220 can be arranged to include any reference cell associated with the class. Again, as will be appreciated, the method reference portion 220 can be implemented in a wide variety of different ways depending on the needs of a particular system. By way of example, in one embodiment, the reference cells are linked together using a link-list construct. Each reference cell can include information that is useful in invoking a method.
  • [0033]
    It should be noted that reference cells are created selectively (e.g., when it is certain and/or when it is likely that a method is to be invoked). Accordingly, in accordance with one embodiment of the invention, if a method does not appear to be invoked, reference cells corresponding to that method are not created. As a result, processing time and memory space may further be improved.
  • [0034]
    As noted above, the method reference portion 220 of FIG. 3 can be arranged to include any reference cell associated with the class. FIG. 4 is a diagrammatic representation of a reference cell 400 in accordance with one embodiment of the present invention. In the illustrated embodiment, the reference cell 400 includes a method name field 402, a method signature field 404, and a code reference field 406. Typically, a value stored in one of the fields 402, 404, and 406 can be referenced (i.e., point to another value). As noted above, a class may have one or more methods associated with it. A class can have one or more corresponding reference cells, for example, the reference cell 300. The method name field 402 is arranged to identify the name of a method associated with the class. This is typically done by storing the actual method name in the method name field 402. However, again, this can also be accomplished by storing a reference or index to the method name.
  • [0035]
    The signature field 404 is arranged to contain or reference a signature associated with the method corresponding the reference cell. The nature of the signature is well known to those familiar with method invocation in Java virtual machines. Typically, in most conventional Java virtual machines, the signature is constructed into a form usable by the virtual machine using a series of calls to the constant pool at runtime when the method is invoked. Although this works well, it is relatively slow. One advantage to including the signature in the reference cell is that a signature suitable for direct use by the virtual machine can be constructed during loading and either stored directly in the reference cell or stored in a location that is referenced by the reference cell. In the described embodiment, the reference cell contains a reference (e.g., pointer or index) to the signature rather than actually storing the signature, simply because signatures can be relatively large and their relative sizes may vary significantly for different classes. In addition, references to signatures can be used across reference cells. Thus, referencing the signature tends to be a more efficient use of memory. More details about internal representation of methods can be found in related U.S. patent application No. ______ (Att.Dkt.No. SUN1P809/P5500), entitled “IMPROVED FRAMEWORKS FOR INVOKING METHODS IN VIRTUAL MACHINES,” U.S. patent application No. ______ (Att.Dkt.No. SUN1P810/P5510), entitled “IMPROVED METHODS AND APPARATUS FOR NUMERIC CONSTANT VALUE INLINING IN VIRTUAL MACHINES,” and U.S. patent application No. ______ (Att.Dkt.No. SUN1P814/P5417), entitled “IMPROVED FRAMEWORKS FOR LOADING AND EXECUTION OF OBJECT-BASED PROGRAMS,” all of which are hereby incorporated herein by reference.
  • [0036]
    Finally, the code reference field 406 is arranged for referencing the code associated with the method. As will be appreciated by those skilled in the virtual machine art, there is often code associated with a method that the virtual machine executes at runtime. The code reference field 406 simply provides a place to identify the location where such information can be or is stored. It should also be noted that the code reference field 406 can be loaded when it is determined that there is a need for the code. Similarly, method name field 402 and method signature field 404 can selectively be loaded.
  • [0037]
    [0037]FIG. 5 illustrates an exemplary loading method 500 for loading a class file in accordance with one embodiment of the invention. The method 500 can be implemented in an object oriented computing environment to selectively load class files into a virtual machine. For the sake of illustration, in the described embodiment, the loading method 500 is used in a Java runtime environment to load a Java class file. Initially, at operation 502, a request to use a class is encountered. Next, at operation 504, a determination is made as to whether an internal representation of the class exists in the virtual machine. If it is determined at operation 504 that an internal class representation does not exist for the class, the method 500 proceeds to operation 506 where the appropriate class file (i.e., class file associated with the class) is loaded into the raw-class heap. After the appropriate class file is loaded into the raw-class heap, at operation 508, an internal representation of the class is created. This internal representation can be, for example, the internal representation 206 illustrated in FIG. 3. Next, at operation 510, the required components of the class are identified and extracted from the raw-class heap. As will be appreciated, these components can be selected, for example, when the class is resolved. Accordingly, only the required components of the class need to be extracted after being identified. Thereafter, the extracted components of the class are loaded into the virtual machine at operation 512. This can include loading required methods and creating references for loaded methods in a method information portion (e.g., similar to a method table implemented in a standard Java class). The method 500 ends following operation 512.
  • [0038]
    On the other hand, if it is determined at operation 504 that an internal class representation exists for the class, the method 500 proceeds to operation 514 where a determination is made as to whether a requested method of the class already exists in the internal class representation in the virtual machine. If it is determined at operation 514 that the requested method of the class already exists in the internal class representation in the virtual machine, the method 500 ends. However, if it is determined at operation 514 that the requested method does not exist in the raw-class heap, the method 500 proceeds to operation 516 where it is determined whether the requested class exists in the raw-class heap. If it is determined at operation 514 that the requested method does not exist, the method 500 proceeds to operation 506 where the appropriate class file is loaded in the raw-class heap. However, if it is determined at operation 516 that the requested class exists in the raw-class heap, the method 500 proceeds directly to operation 510, bypassing operations 506 and 508. At operation 510, the required components of the class are identified and extracted from the raw-class heap. Thereafter, the extracted components of the class can be loaded into the virtual machine at operation 512. As noted above, this can include loading required methods and creating references for loaded methods in a method information portion (e.g., similar to a method table implemented in a standard Java class). The method 500 ends following operation 512.
  • [0039]
    The many features and advantages of the present invention are apparent from the written description, and thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4086626 *Jun 7, 1976Apr 25, 1978Fairchild Camera And Instrument CorporationMicroprocessor system
US4199811 *Sep 2, 1977Apr 22, 1980Sperry CorporationMicroprogrammable computer utilizing concurrently operating processors
US4667290 *Sep 10, 1984May 19, 1987501 Philon, Inc.Compilers using a universal intermediate language
US4910731 *Jul 13, 1988Mar 20, 1990Hitachi, Ltd.Switching system and method of construction thereof
US5418964 *Aug 31, 1994May 23, 1995International Business Machines CorporationSystem and method for parent class shadowing in a statically linked object hierarchy
US5815718 *May 30, 1996Sep 29, 1998Sun Microsystems, Inc.Method and system for loading classes in read-only memory
US5838980 *Jun 25, 1997Nov 17, 1998Sybase, Inc.Compilation and virtual machine arrangement and process for source code including pre-runtime executable language structure constructs
US5872978 *Dec 19, 1996Feb 16, 1999U.S. Philips CorporationMethod and apparatus for improved translation of program data into machine code format
US5878430 *Sep 20, 1996Mar 2, 1999Allen-Bradley Company, LlcObject attribute handler
US5893084 *Oct 4, 1996Apr 6, 1999Gemini Systems, Inc.Method for creating specific purpose rule-based n-bit virtual machines
US5899997 *Apr 1, 1997May 4, 1999Transparency Systems, Inc.Object-oriented query mechanism
US5903761 *Oct 31, 1997May 11, 1999Preemptive Solutions, Inc.Method of reducing the number of instructions in a program code sequence
US5920720 *Feb 25, 1997Jul 6, 1999Microsoft CorporationEfficient computer based virtual machine object structure
US5970242 *Jan 23, 1997Oct 19, 1999Sun Microsystems, Inc.Replicating code to eliminate a level of indirection during execution of an object oriented computer program
US5978585 *Mar 27, 1997Nov 2, 1999Inprise CorporationDevelopment system with improved methods for recompiling dependent code modules
US6003038 *Mar 31, 1997Dec 14, 1999Sun Microsystems, Inc.Object-oriented processor architecture and operating method
US6021469 *Jan 23, 1997Feb 1, 2000Sun Microsystems, Inc.Hardware virtual machine instruction processor
US6026237 *Nov 3, 1997Feb 15, 2000International Business Machines CorporationSystem and method for dynamic modification of class files
US6026485 *Jan 23, 1997Feb 15, 2000Sun Microsystems, Inc.Instruction folding for a stack-based machine
US6047125 *Oct 1, 1997Apr 4, 2000Sun Microsystems, Inc.Garbage collection system for improved use of memory by removal of reference conflicts
US6072951 *Oct 15, 1997Jun 6, 2000International Business Machines CorporationProfile driven optimization of frequently executed paths with inlining of code fragment (one or more lines of code from a child procedure to a parent procedure)
US6072953 *Sep 30, 1997Jun 6, 2000International Business Machines CorporationApparatus and method for dynamically modifying class files during loading for execution
US6075942 *May 4, 1998Jun 13, 2000Sun Microsystems, Inc.Encoding machine-specific optimization in generic byte code by using local variables as pseudo-registers
US6081665 *Dec 19, 1997Jun 27, 2000Newmonics Inc.Method for efficient soft real-time execution of portable byte code computer programs
US6096095 *Jun 4, 1998Aug 1, 2000Microsoft CorporationProducing persistent representations of complex data structures
US6101580 *Apr 23, 1997Aug 8, 2000Sun Microsystems, Inc.Apparatus and method for assisting exact garbage collection by using a stack cache of tag bits
US6118940 *Nov 25, 1997Sep 12, 2000International Business Machines Corp.Method and apparatus for benchmarking byte code sequences
US6151618 *Jun 18, 1997Nov 21, 2000Microsoft CorporationSafe general purpose virtual machine computing system
US6151703 *May 20, 1996Nov 21, 2000Inprise CorporationDevelopment system with methods for just-in-time compilation of programs
US6163780 *Apr 1, 1998Dec 19, 2000Hewlett-Packard CompanySystem and apparatus for condensing executable computer software code
US6182202 *Oct 31, 1997Jan 30, 2001Oracle CorporationGenerating computer instructions having operand offset length fields for defining the length of variable length operand offsets
US6202208 *Sep 29, 1998Mar 13, 2001Nortel Networks LimitedPatching environment for modifying a Java virtual machine and method
US6205578 *Aug 14, 1998Mar 20, 2001Ati International SrlInterpreter for stack-based languages
US6223202 *Jun 5, 1998Apr 24, 2001International Business Machines Corp.Virtual machine pooling
US6260187 *Aug 20, 1998Jul 10, 2001Wily Technology, Inc.System for modifying object oriented code
US6292883 *Sep 28, 1998Sep 18, 2001U.S. Philips CorporationConverting program-specific virtual machine instructions into variable instruction set
US6317872 *Apr 6, 1998Nov 13, 2001Rockwell Collins, Inc.Real time processor optimized for executing JAVA programs
US6324685 *Mar 18, 1998Nov 27, 2001Becomm CorporationApplet server that provides applets in various forms
US6330709 *Mar 30, 1998Dec 11, 2001International Business Machines CorporationVirtual machine implementation for shared persistent objects
US6332215 *Dec 8, 1998Dec 18, 2001Nazomi Communications, Inc.Java virtual machine hardware for RISC and CISC processors
US6338160 *Jan 20, 2000Jan 8, 2002Nazomi Communications, Inc.Constant pool reference resolution method
US6339841 *Apr 16, 1999Jan 15, 2002International Business Machines CorporationClass loading model
US6349377 *Sep 28, 1998Feb 19, 2002U.S. Philips CorporationProcessing device for executing virtual machine instructions that includes instruction refeeding means
US6372286 *Jul 19, 1994Apr 16, 2002Symetrix CorporationBarium strontium titanate integrated circuit capacitors and process for making the same
US6374286 *Apr 6, 1998Apr 16, 2002Rockwell Collins, Inc.Real time processor capable of concurrently running multiple independent JAVA machines
US6412108 *May 6, 1999Jun 25, 2002International Business Machines CorporationMethod and apparatus for speeding up java methods prior to a first execution
US6427228 *May 12, 1999Jul 30, 2002International Business Machines CorporationCombining a meta data file and java source code to dynamically create java classes and javabeans
US6434625 *Jul 13, 1999Aug 13, 2002International Business Machines CorporationGeneralizing data streams to overcome differences in word length and byte order
US6434694 *Jun 29, 1998Aug 13, 2002Sun Microsystems, Inc.Security for platform-independent device drivers
US6442753 *Aug 28, 1997Aug 27, 2002International Business Machines CorporationApparatus and method for checking dependencies among classes in an object-oriented program
US6446084 *Sep 22, 1998Sep 3, 2002Sun Microsystems, Inc.Optimizing symbol table lookups in platform-independent virtual machines
US6446254 *Aug 13, 1999Sep 3, 2002International Business Machines CorporationPackaging memory image files
US6467037 *Jun 30, 1998Oct 15, 2002Sun Microsystems, Inc.Utilizing a program counter with one or more data counters for executing instructions
US6477702 *Nov 9, 2000Nov 5, 2002Sun Microsystems, Inc.Bytecode program interpreter apparatus and method with pre-verification of data type restrictions and object initialization
US6496871 *Jun 30, 1998Dec 17, 2002Nec Research Institute, Inc.Distributed agent software system and method having enhanced process mobility and communication in a computer network
US6553565 *Apr 23, 1999Apr 22, 2003Sun Microsystems, IncMethod and apparatus for debugging optimized code
US6557023 *May 28, 1999Apr 29, 2003Sun Microsystems, Inc.Method and apparatus for avoiding array class creation in virtual machines
US6557054 *Apr 20, 2000Apr 29, 2003Richard R. ReismanMethod and system for distributing updates by presenting directory of software available for user installation that is not already installed on user station
US6571388 *Mar 9, 1999May 27, 2003Hewlett-Packard Development Company, L.P.Building a custom software environment including pre-loaded classes
US6584612 *Jul 15, 1999Jun 24, 2003International Business Machines CorporationTransparent loading of resources from read-only memory for an application program
US6643711 *Mar 19, 2002Nov 4, 2003Sun Microsystems, Inc.Method and apparatus for dispatch table construction
US6658421 *Feb 14, 2000Dec 2, 2003International Business Machines CorporationSystem and method for detecting release-to-release binary compatibility in compiled object code
US6684394 *Aug 28, 2000Jan 27, 2004Stmicroelectronics LimitedRelocation format for linking with relocation instructions containing operations for combining section data
US6704803 *Dec 29, 1998Mar 9, 2004International Business Machines CorporationMethod and system for distributing data events over an information bus
US6704923 *Feb 28, 2000Mar 9, 2004Sun Microsystems, Inc.System and method for pre-verification of stack usage in bytecode program loops
US6738977 *May 31, 2000May 18, 2004International Business Machines CorporationClass sharing between multiple virtual machines
US6851108 *Nov 16, 2000Feb 1, 2005Microsoft CorporationVerifying intermediate language code
US6851111 *Dec 15, 2000Feb 1, 2005International Business Machines CorporationSystem and method for class loader constraint checking
US20020046298 *Jun 30, 1997Apr 18, 2002Lars BakInterpreting functions utilizing a hybrid of virtual and native machine instructions
US20020170041 *Dec 20, 2001Nov 14, 2002Stmicroelectronics LimitedRetrieval of symbol attributes
US20020170043 *Feb 23, 2001Nov 14, 2002Bagley Richard J.Method for dynamically identifying pseudo-invariant instructions and their most common output values on frequently executing program paths
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7913265Jun 7, 2005Mar 22, 2011Gemalto SaMethod of loading software with an intermediate object oriented language in a portable device
US8595396Jan 18, 2006Nov 26, 2013Thomson LicensingSystem and process for acquiring a software code, corresponding host computer and software transmission process and associated products
US8863119 *May 26, 2011Oct 14, 2014Salesforce.Com, Inc.Methods and systems for generating a dynamic workflow in a multi-tenant database environment
US9507613 *Mar 30, 2012Nov 29, 2016Oracle International CorporationMethods and apparatus for dynamically preloading classes
US9569238Sep 17, 2014Feb 14, 2017Salesforce.Com, Inc.Methods and systems for generating a dynamic workflow in a multi-tenant database environment
US20080010649 *Jun 7, 2005Jan 10, 2008Gilles GrimaudMethod Of Loading Software With An Intermediate Object Oriented Language In A Portable Device
US20110296413 *May 26, 2011Dec 1, 2011Salesforce.ComMethods and systems for generating a dynamic workflow in a multi-tenant database environment
US20130263123 *Mar 30, 2012Oct 3, 2013Jiangli ZhouMethods and Apparatus for Dynamically Preloading Classes
EP1684174A1 *Jan 19, 2005Jul 26, 2006Thomson Multimedia Broadband BelgiumSystem and process for incremental loading of software program code, corresponding host computer and software transmission process, and associated products
EP1684175A1 *Jan 5, 2006Jul 26, 2006THOMSON LicensingSystem and process for incremental loading of software program code, corresponding host computer and software transmission process, and associated products
WO2005124544A3 *Jun 7, 2005Feb 23, 2006Gemplus Card IntMethod for loading software with an intermediate object oriented language in a portable device
Classifications
U.S. Classification717/166
International ClassificationG06F9/445
Cooperative ClassificationG06F9/445
European ClassificationG06F9/445
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